Effect of estrogen, testosterone, and phenobarbital on uterine weight and liver microsomal enzymes in prepuberal mice.

Prepuberal female mice were treated with estradiol benzoate (EB), testosterone (T), or phenobarbital (PB), or were untreated. At 8 days after treatment treated mice had lower uterine weights than did untreated mice. Mice treated with EB and PB also had higher levels of hepatic cytochrome P450 at this time. The uteri of mice treated with EB, T, or PB were capable of responding to exogenous EB 8 days following the treatment with an increase in weight. In a second experiment mice were treated with a range of doses of EB, T, or PB,. At the lower doses there was an inverse association of uterine weight and cytochrome P450 levels. At higher doses there was no apparent association. These data indicate that uterine weight may be influenced in part by prior treatment that also affects the level of liver enzymes.